Synthesis and structure elucidation of the condensation products between thiophene dicarbaldehydes and aromatic amines. Potential analgesic and anti-inflammatory agents

Article abstract of DOI:10.1002/jhet.5570250551

Thiophene-3,4-dicarbaldehyde I reacts in the presence of 2-mercaptoethanol to yield N-aryl-5,6-dihydro-4-oxo-4H-thieno[3,4-c]pyrroles 2 and N-aryl-4-arylimino-5,6-dihydro-4H-thieno[3,4-c]pyrroles 3, while thiophene 2,3-dicarbaldehyde 4 reacts with aromatic amines to give N-aryl-5,6-dihydro-6-oxo-4H-thieno[2,3-c]pyrroles 5 in good yields. Labeling experiments and nmr spectral analysis give evidence for the possible reaction mechanism.